/ 12 May 2004

Things that go buzz in the night

After the sun slinks behind the horizon, bands of female anopheles mosquitoes rise from their fetid breeding grounds to wage war on the human species. An insatiable lust for blood ensures the continuation of their type, but their victims can face a consequence more ominous than a sting and an itch.

The four species of anopheles often enjoy an intimate relationship with critters far smaller but infinitely more fearsome: plasmodium, the species of bacterium responsible for malaria.

Once an infected mosquito has bitten a human the parasite makes its way into the liver and then blood, destroying red blood cells and multiplying. Symptoms ranging from fever to fatigue and muscle aches, headaches, nausea, vomiting, abdominal pain and diarrhoea can occur. If malaria is not diagnosed almost immediately, complications can result in death.

Malaria is common in some Amazonian regions, Thailand, Madagascar, the Solomon Islands, Sumatra and Borneo, but the toll is heaviest in sub-Saharan African where 90% of the estimated one million deaths a year occur, mostly among children under five.

A glance at the red band on a map that indicates the regions with the highest prevalence of malaria gives credence to the saying, “People are sick because they are poor and people are poor because they are sick.” Red inevitably marks the spots where poor productivity levels exacerbate poverty and underdevelopment.

In countries where malaria is endemic it may account for up to 40% of public health expenditure, 30% to 50% of in-patient expenditure and 50% of outpatient visits, leaching much-needed resources from health care systems already overburdened by HIV and tuberculosis.

In terms of lost gross domestic product, the illness costs about $12-billion a year, but more debilitating is the emotional toll it has on families, as well as the effect that recurring absenteeism has on children’s education and development.

Apart from a quick swat, humans have an entire armoury available to batter malaria into submission.

“Biological systems are dynamic [and build resistance to poisons and anti-malarial drugs], but we also evolve, we get better,” says Dr Brian Sharp, the director of the malaria research programme of the Medical Research Council.

In the war that was recently waged against malaria in KwaZulu-Natal, a small but significant victory was won.

After years of brooding submission anopheles re-emerged with a vengeance in the 1999/2000 rainy season. The mosquito hadn’t been seen in the province for more than 50 years, but came back fighting fit and with a resistance to the anti-malarial medicine and the pesticide that was being used in the area.

The little clinic in Ndumo close to the Mozambique/Swaziland border was swamped, with more than 30 000 cases reported in 2000. Army tents had to be set up to cope with the influx of patients and the more serious cases were dispatched to the nearby Mosveld hospital where about 500 patients a day were reported — double the usual caseload for all illnesses at the hospital.

“It is no exaggeration to say that there tended to be one person sleeping on a bed and two sleeping below it,” says Dr Hervey Vaughan Williams, medical manager at the hospital.

To cope with the crisis a comprehensive malaria control programme was implemented in the province. Residents in high-risk areas were given insecticide-treated nets to sleep under, DDT was reintroduced for controlled house spraying and sulfadoxine-pyrimethamine — the drug that had been used for first-line treatment — was replaced by a more effective artemisinin-based combination therapy. People in the area were also educated on preventative measures and recognising symptoms of malaria as well as how to take the anti-malarial drugs.

“Malaria control is about layers. You need a good drug in collaboration with vector [carrier insect] control,” says Sharp.

By 2001 the number of malaria cases had dropped to about 3 600 at Ndumo clinic and by 2003 only 110 cases were reported. These events proved that malaria can be controlled if tackled with a multi-pronged approach. But as in all battles there is no room for complacency.

South Africa has only isolated pockets where malaria occurs, making it easier to blitz than in countries where it is endemic.

According to Dr Abdullah Ali, a medical practitioner and malaria programme manager on the East African island of Zanzibar, the problem is more complicated in sub-Saharan Africa. The health information system may be weak, accurate records aren’t often kept, health care may be further burdened by civil war, and proper diagnosis and effective drugs are difficult to come by, particularly in rural settings. “We look at the entire system and it is broken,” he says.

People in rural areas will often buy anti-malarial drugs such as chloraquin directly from their local shop, but this drug has lost its effectiveness, with failure rates as high as 60% to 70% in more than 35 countries.

Small shops aren’t licensed to stock artemisinin-based combination therapies and in the event that people do access these drugs, there is the danger that they don’t finish taking the entire course of tablets.

Professor Ronald Green-Thompson, the head of the KwaZulu-Natal department of health, points out that for malaria control to be truly effective it needs to be tackled on a continent-wide scale. Political cooperation, teamwork with neighbouring countries and more resources are also vital.

“Cuba has eradicated malaria. Cuba is an island, but Africa is just a bigger island,” he says. “We need to be bold enough to learn from each other [in Africa] and intelligent so that we can say ‘teach us how we can learn from you’.”